When to plant watermelons in Klagenfurt: 3 July – 27 July

In Klagenfurt, watermelon: sow for seedlings from 15 May to 29 June; plant into a greenhouse from 12 June to 27 July; plant out into open ground from 3 July to 27 July. For plants and seeds, the places nearby include Gärtnerei Hübner (garden centre, 2 km) and Dehner (garden centre, 3 km); addresses and opening hours are below.

Watermelon in Klagenfurt: soil, season and weather

In Klagenfurt the soil, not frost, sets the date: the last frost is over around 21 May, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 3 July, 43 days later. 83 days separate planting out (3 July) from the first autumn frost (24 September); the card's 59 days to the first harvest leave 24 for picking, so a start 3 weeks late would still fit.

Last spring frost	21 May
Top 7 cm of soil at 18 °C	3 July, 43 days after the last frost
Into an unheated greenhouse	12 June – 27 July; June outside: 7.7 °C at night, 17.2 °C by day; card 18–35 °C
First autumn frost	24 September, 83 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	31 August – 24 September
Days left for picking	24
Daylight	15:40 on 5 June, 15:45 on 3 July
Watering outdoors when fruiting (card)	every 5 days; the driest month, August, has 15 rainy days

The same dates in Klagenfurt hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Klagenfurt: care after planting

Planted on 3 July: in the first weeks water every 5 days.

Feeding, by the card’s schedule from that day:

3 July — feed: balanced (NPK)

Pests and diseases of watermelon to watch for:

Dates count from the first planting day of the window above; a later planting moves them by as many days.

Weather in Klagenfurt during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 18.6 °C. Months that stay below 18 °C even by day on average: September (13.6 °C). Nights average below 18 °C in every month of the season, from 4.9 °C to 9.1 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
July	18.6	9.1	135	18	15:30
August	18.3	9	130	15	14:14
September	13.6	4.9	153	15	12:36

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

All the nearest cities on our list plant watermelon earlier than Klagenfurt; the closest date is in Salzburg, 24 days earlier.

City	Distance	Date	Difference
Graz	99 km	8 June – 1 August	25 days earlier
Udine	102 km	23 May – 13 August	41 days earlier
Trieste	115 km	5 June – 19 August	28 days earlier
Zagreb	157 km	28 May – 13 August	36 days earlier
Salzburg	163 km	9 June – 22 July	24 days earlier
Linz	188 km	4 June – 3 August	29 days earlier

Where to buy watermelon plants and seeds near Klagenfurt

Buy plants ready to set out from 3 July to 27 July (from 12 June to 27 July for an unheated greenhouse); seed for raising your own is sown from 15 May to 29 June. Within 15 km of Klagenfurt OpenStreetMap lists 11 garden centres, 1 plant nursery, 2 markets and 7 farm shops (collected 28 October 2026).

Gärtnerei Hübner — garden centre
Pischeldorfer Straße 62, Klagenfurt am Wörthersee · 2 km
Dehner — garden centre
Südring 357, 9020 Klagenfurt am Wörthersee · 3 km
Bellaflora — garden centre
Völkermarkter Straße 252, 9020 Klagenfurt am Wörthersee · 4 km
Mattuschka Staudengärtnerei — garden centre
Emmersdorfer Straße 86, 9061 Klagenfurt am Wörthersee · 6 km

Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

Questions